Horn switch gear and airbag system

ABSTRACT

A horn switch gear includes a backward moving body, a stationary body, a biasing member, and a pair of contact members. The backward moving body, which is configured to move backward, faces the stationary body. The biasing member, which is interposed between the backward moving body and the stationary body, biases the backward moving body in a restoring direction. The contact members, which are brought into or out of contact with each other by a forward or backward movement of the backward moving body, are moved together with the backward moving body. The stationary body includes an interposition which is interposed between the contact members for separating the contact members while the backward moving body is in a restored position, and which moves away from between the contact members to bring the contact members into contact with each other while the backward moving body is in a backward position.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.10/798,645, filed Mar. 12, 2004, now U.S. Pat. No. 6,881,911 which isincorporated by reference in its entirety.

BACKGROUND

The present invention relates to a horn switch and, more preferably, toa horn switch gear provided to an airbag system such that a module coveror an airbag system moves backward by pressure applied by an occupant.The present invention also relates to an airbag system including thehorn switch gear.

Driver-seat airbag systems mounted on steering wheels of cars includeone in which when a module cover of the airbag system is pushed, a hornswitch is turned on to blow a horn. For example, Japanese UnexaminedPatent Application Publication Nos. 10-100832 and 2001-114057 describedriver-seat airbag systems in which when an airbag system is pushed, amodule cover moves backward to turn on a horn switch.

In known horn switch gears, one of the contact members is mounted to amodule cover and the other is attached to a retainer. However, providingseparate contact members increases the difficulty of assembly work whichmust be done with high accuracy.

Accordingly, it is an object of the present invention to provide a hornswitch gear having a pair of contact members at only one of a backwardmoving body such as a module cover and a stationary body such as aretainer to facilitate the positioning of the contact members and anairbag system including the horn switch gear.

SUMMARY

According to an embodiment of the invention, a horn switch gear isprovided. The gear includes a backward moving body configure to movebackward by pressure applied by an occupant; a stationary body facingthe backward moving body; a biasing member interposed between thebackward moving body and the stationary body for biasing the backwardmoving body in a restoring direction; and a pair of contact members thatare brought into or out of contact with each other by a forward or thebackward movement of the backward moving body. The contact members aremoved forward or backward together with the backward moving body. Thestationary body includes an interposition which is interposed betweenthe contact members for separating the contact members from each otherwhile the backward moving body is in a restored position and which isconfigured to bring the contact members into contact with each otherwhile the backward moving body is in a backward position.

In an embodiment of a horn switch gear, the stationary body may includea guide for guiding at least one of the contact members to bring thecontact members into contact with each other when the backward movingbody is moved backward from the restored position.

An embodiment of a horn switch gear according to the invention includes:a backward moving body configured to move backward by pressure appliedby an occupant; a stationary body facing the backward moving body; nbiasing member interposed between the backward moving body and thestationary body for biasing the backward moving body in the restoringdirection; and a pair of contact members that are brought into or out ofcontact with each other by a forward or backward movement of thebackward moving body. The contact members are retained by the stationarybody. The backward moving body includes an interposition which isinterposed between the contact members for separating the contactmembers from each other while the backward moving body is in a restoredposition and which moves away from between the contact members to bringthe contact members into contact with each other while the backwardmoving body is in a backward position.

In an embodiment of a horn switch gear, the backward moving body mayinclude a guide for guiding at least one of the contact members bycoming into contact with it to bring the contact members into contactwith each other when the backward moving body is moved backward from therestored position.

An embodiment of a horn switch gear according to the invention includes:a backward moving body configured to move backward by pressure appliedby an occupant; a stationary body facing the backward moving body; abiasing member interposed between the backward moving body and thestationary body for biasing the backward moving body in a restoringdirection; and a pair of contact members that are brought into or out ofcontact with each other by a forward or backward movement of thebackward moving body. The contact members are separated from each otherwhile the backward moving body is in a restored position. The contactmembers are moved forward or backward together with the backward movingbody. The stationary body includes a guide for guiding at least one ofthe contact members by coming into contact with it to bring the contactmembers into contact with each other when the backward moving body ismoved backward from the restored position.

An embodiment of a horn switch gear according to the invention includes:a backward moving body configured to move backward by pressure appliedby an occupant; a stationary body facing the backward moving body; abiasing member interposed between the backward moving body and thestationary body for biasing the backward moving body in a restoringdirection; and a pair of contact members that are brought into or out ofcontact with each other by a forward or backward movement of thebackward moving body. The contact members are separated from each otherwhile the backward moving body is in a restored position. The contactmembers are retained by the stationary body. The backward moving bodyincludes a guide for guiding at least one of the contact members bycoming into contact with it to bring the contact members into contactwith each other when the backward moving body is moved backward from therestored position.

An embodiment of a horn switch gear according to the invention includes:a backward moving body configured to move backward by pressure appliedby an occupant; a stationary body facing the backward moving body; abiasing member interposed between the backward moving body and thestationary body for biasing the backward moving body in a restoringdirection; and a pair of contact members that is brought into or out ofcontact with each other by a forward or backward movement of thebackward moving body. The contact members are moved forward or backwardtogether with the backward moving body. The stationary body includes aninterposition which moves away from between the contact members to bringthe contact members into contact with each other while the backwardmoving body is in a restored position and which is interposed betweenthe contact members for separating the contact members from each otherwhile the backward moving body is in a backward position.

An embodiment of a horn switch gear according to the invention includes:a backward moving body configured to move backward by pressure appliedby an occupant; a stationary body facing the backward moving body; abiasing member interposed between the backward moving body and thestationary body for biasing the backward moving body in a restoringdirection; and a pair of contact members that are brought into or out ofcontact with each other by a forward or backward movement of thebackward moving body. The contact members are retained by the stationarybody. The backward moving body includes an interposition which movesaway from between the contact members to bring the contact members intocontact with each other while the backward moving body is in a restoredposition and which is interposed between the contact members forseparating the contact members from each other while the backward movingbody is in a backward position.

In an embodiment of a horn switch gear according to the invention, thebackward moving body may be an airbag system, a module cover, or amodule cover of an airbag system.

In an embodiment of a horn switch gear, while the backward moving body(which may be, for example, a module cover or an airbag system) is in arestored position (i.e., in an unpushed condition), the contact membersmay be separated from each other. When the backward moving body ispushed, the interposition may move away from between the contact membersto bring the contact members into contact with each other, therebyblowing a horn.

In an embodiment of a horn switch gear, it is also possible to include aguide for guiding at least one of the contact members which comes intocontact with it to bring the contact members into contact with eachother when the backward moving body is moved backward from the restoredposition. With such a structure, the contact members may be forced bythe guide to come into contact with each other, increasing the contactpressure of the contact members.

In an embodiment of a horn switch gear, when the backward moving bodymoves backward, the contact members may be guided by a guide to comeinto contact with each other to blow the horn.

In an embodiment of a horn switch gear, while the backward moving body(which may be, for example, a module cover or an airbag) is in arestored position, the contact members may be in contact with eachother. A horn control circuit may be constructed not to bring the horninto conduction with the contact members in a closed condition.

In an embodiment of a horn switch gear, when the backward moving bodymoves backward, the interposition may enter the contact members toseparate them from each other, i.e., to open the contact members. A horncontrol circuit may bring the horn into conduction to blow the horn.

In an embodiment of a horn switch gear, the horn switch gear may havecontact members at only one of the backward moving body and thestationary body. As a result, the positioning of the contact members maybe easy, making it easy to assemble the airbag system and so on.

An embodiment of a horn switch gear according to the present inventionincludes: a moving body configured to move backward by pressure appliedby an occupant; a stationary body facing the backward moving body; abiasing member interposed between the moving body and the stationarybody; a pair of contact members that are configured to be brought intoor out of contact with each other by a forward or backward movement ofthe moving body; and an interposition which: is interposed between thecontact members when the moving member is in a first position, and isnot interposed between the contact members when the moving member is ina second position. The contact members either are retained by thestationary body or are moved together with the moving body.

In an embodiment of a horn switch according to the present invention,the first position may a restored position and the second position is abackward position. Similarly, the first position may be a backwardposition and the second position may be a restored position.

In an embodiment of a horn switch according to the present invention,the interposition may be part of the stationary body or part of themoving body.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory only,and are not restrictive of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features, aspects, and advantages of the presentinvention will become apparent from the following description, appendedclaims, and the accompanying exemplary embodiments shown in thedrawings, which are briefly described below.

FIG. 1 is a sectional view of an embodiment of an airbag systemincluding an embodiment of a horn switch gear according to the presentinvention;

FIGS. 2A and 2B are sectional views the horn switch gear of FIG. 1 inwhich FIG. 2A is a non-contact (i.e., a restored position) view and FIG.2B is an in-contact (i.e., a backward position) view;

FIG. 3 is an exploded perspective view of the horn switch gear of FIG.1;

FIG. 4 is an exploded perspective view of the horn switch gear of FIG.1;

FIG. 5 is an exploded perspective view of the airbag system of FIG. 1;

FIGS. 6A and 6B are sectional views of a second embodiment of a hornswitch gear according to the present invention;

FIG. 7 is an exploded perspective view of the horn switch gear of FIGS.6A and 6B;

FIG. 8 is an exploded perspective view of the horn switch gear of FIGS.6A and 6B;

FIGS. 9A and 9B are sectional views of a third embodiment of a hornswitch gear according to the present invention;

FIG. 10 is an exploded perspective view of the horn switch gear of FIGS.9A and 9B;

FIG. 11 is an exploded perspective view of the horn switch gear of FIGS.9A and 9B;

FIGS. 12A and 12B are sectional views of a fourth embodiment of a hornswitch gear according to the present invention;

FIGS. 13A and 13B are sectional views of a fifth embodiment of a hornswitch gear according to the present invention;

FIG. 14 is a sectional view of a sixth embodiment of a horn switch gearaccording to the present invention;

FIG. 15 is a sectional view of the horn switch gear of FIG. 14; and

FIG. 16 is an exploded perspective view of the horn switch gear of FIG.14.

DETAILED DESCRIPTION

Embodiments of the present invention will be described hereinafter withreference to the drawings. FIG. 1 shows an airbag system 1 having a hornswitch gear 70 according to an embodiment of the invention in sectionalview. FIGS. 2A and 2B show the horn switch section of FIG. 1 in enlargedview. FIGS. 3 and 4 shows the horn switch gear 70 in exploded view,viewed from opposite directions from each other. And, FIG. 5 shows theairbag system 1 in exploded perspective view. FIG. 2A shows an“unpushed” state in which a module cover 40 is not pushed. FIG. 2B showsa “module-cover pushed state” in which the module cover 40 is pushed toblow a horn.

The airbag system 1 is a driver-seat airbag system mounted in the centerof a steering wheel. The airbag system 1 includes a metal retainer 10,an airbag 20 mounted to the retainer 10 with an airbag-mounting ring 24,an inflator 30 for inflating the airbag 20, a synthetic-resin modulecover 40 which covers the folded airbag 20, and a horn switch gear 70.

The module cover 40 has a grooved tear line 40 a. The module cover 40 istorn open along the tear line 40 a when the airbag 20 is inflated by theinflator 30. The airbag 20 is not shown in FIG. 5.

As clearly shown in FIGS. 1 and 5, the retainer 10 includes asubstantially rectangular main plate 11. The main plate 11 has anopening 12 for the inflator 30 to be inserted. Around the opening 12 isprovided an insertion hole 13 for a stud bolt 25 rising from theairbag-mounting ring 24.

An anchor piece 14 rises from the outer periphery of the main plate 11of the retainer 10 toward the lower part in the drawing (opposite to anoccupant). The anchor piece 14 is for mounting the airbag system 1 to asteering wheel. The anchor piece 14 has an opening 14 a for a bolt orthe like to be inserted. The opening 14 a may be a bolting screw hole.

A peripheral wall 15 rises from substantially the whole outercircumference of the main plate 11 (except the part of the anchor piece14) upward in the drawing (toward the occupant). Extensions 16 extendsideward (laterally from the airbag system 1) from the rising end of theperipheral wall 15.

To each extension 16, a metal nut 17 into which a metal guide shaft 50is screwed is firmly fixed by welding, caulking, or integral molding.

The periphery of an inflator insertion hole 22 of the airbag 20 issuperposed on the periphery of the inflator opening 12 of the retainermain plate 11, on which the airbag-mounting ring 24 is superposed. Astud bolt 25 is inserted into a bolt insertion hole formed around theperiphery of the inflator insertion hole 22 of the airbag 20. The studbolt 25 is inserted into the bolt insertion hole 13 of the retainer 10.The stud bolt 25 is further inserted into a bolt insertion hole 32 of aflange 31 of the inflator 30 and tightened with a nut 26 (FIG. 1). Thus,the airbag 20 and the inflator 30 are fixed to the retainer 10.

The module cover 40 includes a main surface 41 facing the occupant and aleg piece 42 rising from the back of the main surface 41. The leg piece42 is integrated with the main surface 41 by synthetic-resin injectionmolding into a nearly rectangular frame shape similar to the peripheralwall 15 of the retainer 10. The peripheral side 41 a of the main surface41 extends outward from the leg piece 42.

The nearly rectangular-frame-shaped leg piece 42 has cutaway portions 43cut from the rising end of the leg piece 42. The cutaway portions 43 areconstructed to receive the extensions 16 of the retainer 10. The legpiece 42 also has rivet holes 44.

The leg piece 42 has a metal frame 60 mounted thereto. The frame 60includes a frame body 61 surrounding the outer surface of the leg piece42 and overhangs 63 extending laterally from the frame body 61.

The frame body 61 has rivet holes 64 (FIG. 5). The rivet holes 64 andthe leg piece 42 are interposed on each other, which are riveted (notshown) through the rivet holes 44 and 64, and so the frame 60 is fixedto the leg piece 42.

The frame body 61 has cutaway portions 62 having a size and anarrangement corresponding to the rim of the cutaway portions 43 of theleg piece 42. The cutaway portions 43 and 62 receive the extensions 16of the retainer 10.

Each overhang 63 has an insertion hole 68 for the guide shaft 50.

Referring to FIG. 2, the lower end of the guide shaft 50 is screwed intothe nut 17 of each extension 16 to be fixed to the extension 16, risingfrom the extension 16 toward the occupant. The guide shaft 50 has aflange 51 serving as a stopper at the upper rim. The horn switch gear 70is provided so as to be fitted on the guide shaft 50.

The structure of the horn switch gear 70 will be described mainly withreference to FIGS. 2 to 4.

The horn switch gear 70 includes an anode 80, a slide cylinder 90, acathode 100, a coil spring 110, an insulation ring 120, and a washer130, as shown in FIGS. 3 and 4.

The anode 80 includes a washer-shaped ring flange 81 and a plurality of(three in this embodiment) tongue-shaped contacts 82 rising from theinner periphery of the flange 81 in the same directions.

The slide cylinder 90 includes a tubular cylinder body 91, a flange 92extending from one end of the cylinder body 91 along the axial center,and pawls 93 (FIG. 4) extending from the end of the cylinder body 91 inparallel to the axial center. The flange 92 has three arc-shaped slits94 extending along the outer periphery of the cylinder body 91 aroundthe inner periphery thereof.

The cathode 100 includes a flange 101 and three tongue-shaped contactscircumferentially rising from the inner periphery of the flange 101. Asshown in FIG. 2, the lower end of each contact 102 is curved toward thecenter of the cathode 100.

The insulation ring 120 includes a flange 121, a nearly cylindricalinner wall 122 rising from the flange 121, and three outer walls 123rising along the outer periphery of the inner wall 122. The part of theinner wall 122 facing the outer walls 123 has windows (also referred toas “window openings”) 124. Each window 124 extends from the innerperiphery of the flange 121 toward the rising end of the inner wall 122.The upper rim of the windows 124 is located slightly lower than theupper end of the outer wall 123 (adjacent to the flange 121).

As shown in FIG. 2, the upper rim of the windows 124 forms an inclinedsurface 124 a that is closer to the outer wall 123 at the upper part.The upper end of the outer wall 123 forms an inclined surface 123 a thatis closer to the inner wall 122 at the lower part. The inclined surface123 a serves as guide for guiding the contact 102 to bring it intocontact with the contact 82.

Each contact 102 of the cathode 100 is slidably superposed on the outercircumference of the inner wall 122. When the module cover 40 is inrestored (i.e., in an unpushed, non-contact condition), the lower end ofthe contact 102 is in contact with the inner-wall inclined surface 124 a(FIG. 2A). When the module cover 40 is pushed into a backward position,the lower end of the contact 102 is separated from the inclined surface124 a but is brought into contact with the inclined surface 123 a at theupper end of the outer wall 123 and the contact 82 of the anode 80 (FIG.2B). The outer circumference of the inner wall 122 and the innercircumference of the outer wall 123 are in an approximately equal radiusrelative to the central axis of the insulation ring 120.

The inner wall 122 has cutaway portions 126 at three locations of theupper end thereof. The flange 121 of the insulation ring 120 has cutawayportions 127 at three locations of the outer periphery thereof.

The washer 130 has three protrusions 131 to be cut in the cutawayportions 127. The protrusions 131 have a rising height larger than thethickness of the flange 121, projecting upward from the upper surface ofthe flange 121 with the horn switch gear 70 in an assembled condition(FIG. 2).

The coil spring 110 has a diameter so as to be fitted on the outer wall123 and brought into contact with the flange 121 and the flange 101 ofthe cathode 100.

As shown in FIG. 2, each contact 82 of the anode 80 is inserted into theslit 94 of the slide cylinder 90 and superposed on the outercircumference of the cylinder body 91. The flange 81 of the anode 80 issuperposed on the flange 92 of the slide cylinder 90, which are fixedtogether with an adhesive or the like as necessary.

The flange 101 of the cathode 100 is superposed on the flange 92, whichare fixed together with an adhesive or the like as necessary. Thecathode 100 and the slide cylinder 90 may be fixed together byengagement or the like.

The coil spring 110 is fitted on the outer circumference of the outerwalls 123 of the insulation ring 120. The insulation ring 120 iscoaxially arranged around the outer circumference of the cylinder body91 such that the inner wall 122 is inserted between the contacts 82 and102. The pawls 93 of the slide cylinder 90 are inserted and locked intothe guide-shaft insertion hole 68 of the frame 60.

The flange 121 located at the lower end of the horn switch gear 70 issuperposed on the extension 16 through the washer 130. The lower end ofthe coil spring 110 is in contact with the protrusions 131 of the washer130, while the upper end of the coil spring 110 is in contact with theflange 101 of the cathode 100. Thus, the cathode 100 is brought intoconduction with the retainer 10 through the coil spring 110 and thewasher 130. Since the retainer 10 is mounted to a steering wheel (notshown), the cathode 100 is brought into conduction with the cathode of abattery of a vehicle. The anode 80 is in close contact with theoverhangs 63 to be brought into contact with the anode of the batterythrough a lead wire (not shown) connecting to the overhangs 63.

In the airbag system 1 including the horn switch gear 70 with such astructure, the upper part of each window 124 of the insulation ring 120interposes between the contacts 82 and 102, thus separating the contacts82 and 102 from each other (FIG. 2A) until the module cover 40 ispushed. Thus, the upper part of the windows 124 of the inner wall 122serves as interposition (i.e., a separating element) for separating thecontacts 82 and 102 from each other.

The module cover 40 is pushed upward toward a restored position (FIG.2A) by the coil spring 110. The pawls 93 are brought into contact withthe flange 51 of the guide shaft 50 by the pressure of the coil spring110.

Referring to FIG. 2B, when the module cover 40 is pushed by an occupant,the frame 60 integrated with the module cover 40 moves back downward tocontract the coil spring 110 by pressure, thereby moving the slidecylinder 90, the anode 80, and the cathode 100 downward. Accordingly,the contacts 82 and 102 also move downward together therewith, thecontacts 102 being pushed inward by the inclined surfaces 123 a, so thatthe contacts 82 and 102 are brought into contact with each other to blowthe horn.

When the occupant releases the pressure applied to the module cover 40,the module cover 40 is moved back into the restored position of FIG. 2Aby the repulsive force of the coil spring 110, thereby stopping thehorn.

As previously described, both of the anode 80 and the cathode 100 of thehorn switch gear 70 are arranged to the module cover 40, improving thepositioning accuracy of the anode 80 and the cathode 100 when assembledto the module cover 40.

Referring to FIGS. 6 to 8, a horn switch gear 70A according to a secondembodiment will be described.

In this embodiment, an anode 140 includes a flange 141 and threecontacts 142 rising from the outer periphery of the flange 141.

A slide cylinder 150 has an inner wall 151 and outer walls 153 risingfrom the inner and the outer peripheries of a flange 152, respectively.The flange 152 has slits 154 for the contacts 142 to pass through. Fromthe inner periphery of the flange 152, pawls 155 project in thedirection opposite to the inner wall 151.

A cathode 160 has a cylindrical contact 161 and a collar 162 projectinginwardly from the upper periphery of the cylindrical contact 161.

An insulation ring 170 has an inner cylinder 171, an outer cylinder 172,a bottom 174 connecting them together, windows (also referred to as“window openings”) 173 shaped to cut the intersection between the bottom174 and the outer cylinder 172, and inclined surfaces 172 a formed atthe upper rims of the windows 173. The inclined surfaces 172 a are eachtapered so as to be reduced in diameter at the lower part.

The upper parts of the windows 173 of the outer cylinder 172 serve asinterposition (i.e., a separating element) for separating the contacts142 and 161 from each other.

A washer 180 has protrusions 181 which come into the windows 173 forsupporting the lower end of the coil spring 110.

The contact 161 of the cathode 160 is superposed on the outer surface ofthe inner wall 151 of the slide cylinder 150, as shown in FIG. 6, andthe collar 162 is brought into contact with the upper end of the coilspring 110. Thus, the contact 161 of the cathode 160 is brought intoconduction with the vehicle body through the coil spring 110 and thewasher 180. The collar 162 overlaps with the flange 152 of the slidecylinder 150.

The lower part of the contact 161 is arranged between the outer cylinder172 of the insulation ring 170 and the inner wall 151 of the slidecylinder 150. The contacts 142 of the anode 140 are arranged outside theouter cylinder 172.

The other arrangement in FIGS. 6 to 8 is similar to that of the firstembodiment.

As shown in FIG. 6A, the outer cylinder 172 is interposed between thecontacts 142 and 161, thereby separating the contacts 142 and 161 fromeach other when the module cover 40 is in unpushed (i.e., restored)position.

When the module cover 40 is pushed by an occupant, the anode 140 and thecathode 160 are pushed down together with the slide cylinder 150,thereby letting the contacts 142 of the anode 140 move into the windows173 under the force of an inward elasticity of the contacts 142. Whenthe anode contacts 142 enter the windows 173, they come into contactwith the contact 161 of the cathode 160 (FIG. 6B), thereby blowing thehorn. When the occupant releases the pressure applied to the modulecover 40, the module cover 40 is pushed back to the restored position ofFIG. 6A by the coil spring 110. At that time, the upper parts of thewindows 173 of the outer cylinder 172 enter the contacts 142 and 161 andseparate them from each other, thereby stopping the horn.

Referring to FIGS. 9 to 11, a horn switch gear 70B according to a thirdembodiment will be described.

This embodiment includes a truncated-cone shaped tapered section 16A onthe upper surface of the extension 16 of the retainer 10, the guideshaft 50 being arranged coaxially with the tapered section 16A.

In this embodiment, an anode 200 includes a flange 201 and threecontacts 202 rising from the inner periphery of the flange 201.

An insulation ring 210 includes a flange 211, inner walls 212 and outerwalls 214 rising from the inner and the outer peripheries of the flange211, respectively, elastic deformation sections 213 extending from theends of the inner walls 212 in parallel with the outer walls 214, pawls215 projecting from the flange 211 in the opposite direction to theinner walls 212, and slits 216 provided in the flange 211 between theinner walls 212 and the outer walls 214.

A cathode 220 includes a cylindrical contact 221 and collars 222projecting outward from one end of the contact 221.

As shown in FIGS. 9A and 9B, the contacts 202 and 221 are insertedbetween the inner walls 212 and the outer walls 214 of the insulationring 210. The contacts 202 of the anode 200 pass through the slits 216and overlap with the outer surfaces of the inner walls 212 and theelastic deformation sections 213, while the contact 221 of the cathode220 overlaps with the inner surfaces of the outer walls 214.

The cathode collars 222 overlap with the flange 211 of the insulationring 210, with which the upper end of the coil spring 110 is broughtinto contact. The lower end of the coil spring 110 is brought intocontact with the upper surface of the extension 16. Thus, the cathode220 comes into conduction with the vehicle body through the coil spring110.

As shown in a restored position shown in FIG. 9A, the elasticdeformation sections 213 overlap with the outer surface of the taperedsection 16A or is slightly separated therefrom until the module cover 40is pushed. When the module cover 40 is pushed into a backward positionby an occupant, the elastic deformation sections 213 are pushed downalong the tapered section 16A to expand like straddle legs, as shown inFIG. 9B. Thus, the contacts 202 of the anode 200 overlapping with theouter surfaces of the elastic deformation sections 213 are brought intocontact with the contact 221 of the cathode 220 to blow the horn.

When the occupant releases the pressure applied to the module cover 40,the module cover 40 moves back to the restored position (FIG. 9A) bymeans of the coil spring 110, thereby stopping the horn.

In the previously described embodiments, the contacts of the horn switchgear are closed to thereby blow the horn. It is also possible, however,to have a horn control circuit which supplies no power to the horn whilethe contacts are closed but which, upon opening the contacts, suppliespower to the horn. FIGS. 12A and 12B show an example of such the hornswitch gear. The horn switch gear 70C is constructed such that, in thehorn switch gear 70 shown in FIGS. 1 to 5, contacts 102A and contacts 82are in contact with each other (FIG. 12A) until the module cover 40 ispushed into a backward position by an occupant (FIG. 12B). When themodule cover 40 is pushed, the inner walls 122A of the insulation ringenter the contacts 82 and 102A and separate them from each other.Reference numeral 123A indicates an insulation-ring outer wall. Theother arrangement of FIGS. 12A and 12B is the same as that of FIG. 2.Similarly, the embodiments of FIGS. 6 to 11 may also be constructed toblow the horn by opening the contacts.

The above embodiments are merely examples of the present invention. Theinvention may employ other arrangements different from those in thedrawings. For example, in the above embodiments, the contacts may not befixed to the module cover 40 but rather to the extension 16 such as, forexample, as shown in the embodiment shown in FIGS. 13A and 13B.

FIGS. 13A and 13B show an embodiment of a horn switch gear 70′ in whichthe horn switch gear 70 of FIG. 2 is essentially flipped vertically. Inthis embodiment, however, the pawls 93′ rise from the inner periphery ofthe flange 121 of the insulation ring. The remain portions of the hornswitch gear 70′ are the same as that of the horn switch gear 70, whereinthe same numerals indicate the same components.

As shown in FIG. 13A, while the module cover 40 is not pushed (i.e., themodule 40 is in a restored position), the contacts 82 and 102 areseparated from each other, whereas when the module cover 40 is pushedinto a backward position (FIG. 13B) by an occupant, the contacts 82 and102 are brought into contact with each other, thereby blowing the hornin a manner substantially similar to the horn switch gear 70 shown inFIG. 2.

FIG. 14 is a sectional view of a horn switch gear 70D according toanother embodiment with a module cover in an unpushed condition (i.e.,in a restored position). FIG. 15 is a sectional view of the horn switchgear 70D with the module cover in a pushed condition (i.e., in abackward position). And, FIG. 16 is an exploded perspective view of thehorn switch gear 70D.

Referring to FIG. 16, the horn switch gear 70D includes an anode 240, aslide cylinder 250, a cathode 260, the coil spring 110, an insulationring 270, and a washer 280.

The anode 240 includes a washer-shaped ring flange 241 and twotongue-shaped contacts 242 rising from the outer periphery of the flange241 in the same direction and around the axial center of the flange 241at regular intervals.

The slide cylinder 250 includes a tubular cylinder body 251, two firstcollars 252 extending radially from one end of the cylinder body 251along the axial center, two second collars 253 which extending radiallyoutward from the outer circumference of the cylinder body 251 at evenintervals from one end of the first collars 252 toward the other end ofthe first collars 252 along the axial center (hereinafter, the other endis lower and the one end is upper), outer walls 254 rising downwardalong the outer circumference of the cylinder body 251 from the distalends of the extensions of the second collars 253, and a pair of facingpieces 255 projecting from the outer circumference of the cylinder body251 so as to face the lower surfaces of the first collars 252.

An upper part of the cylinder body 251 (in the axial direction) islarger in diameter than a lower part of the cylinder body 251; a step251 a is formed between the upper and lower parts. The step 251 a isflush with the lower surface of the second collars 253.

The first collars 252 and 252 are arranged around the axial center ofthe cylinder body 251 at even intervals. The second collars 253 and 253are arranged around the axial center of the cylinder body 251 at evenintervals with a phase difference of 90° from the first collars 252.

The outer walls 254 each have a guide hole 254 a for a later-describedguide projection 275 to be fitted. The guide hole 254 a extends downward(toward the distal end) from the base end of the outer wall 254 so as tocut out the end rim of the second collar 253.

Each facing piece 255 can be elastically displaced from the lowersurface of the first collar 252 substantially in the direction towardand away therefrom. The facing pieces 255 and the first collars 252elastically clamp the periphery of the guide-shaft insertion hole 68provided in the overhang 63 of the frame 60 that supports the upper partof the horn switch gear 70D.

The interval between the lower surface of the first collar 252 and theupper surface of the second collar 253 is substantially the same as thetotal thickness of the periphery of the guide-shaft insertion hole 68and the flange 241 of the anode 240.

The slide cylinder 250 is constructed of an insulative synthetic resinor the like.

The cathode 260 includes a ring-shaped flange 261 and two tongue-shapedcontacts 262 rising downward from the outer periphery of the flange 261.The contacts 262 and 262 are arranged around the axial center of theflange 261 at even intervals. The interval between the contacts 262 and262 is larger than the outer diameter of the coil spring 110 and smallerthan the interval between the contacts 242 and 242 of the anode 240.

The insulation ring 270 includes a ring-shaped flange 271 and acylindrical peripheral wall 272 rising from the outer periphery of theflange 271. The outer diameter of the peripheral wall 272 is equal to orslightly smaller than the interval between the inner surfaces of theouter walls 254 and 254 of the slide cylinder 150 and equal to orslightly larger than the space between the contacts 242 and 242 of theanode 240.

The peripheral wall 272 has two windows (also referred to as “windowopenings”) 273 having a size for each contact 262 of the cathode 260 topass through. The inner circumference of the peripheral wall 272 hasguide grooves 274 (FIGS. 14 and 15), from the upper rim to the windows273, for guiding the contacts 262 into the windows 273. The lower rim ofeach window 273 forms an inclined surface 273 a which is inclineddownward and outwardly (radially) from the peripheral wall 272 such thata lower part of the inclined surface 273 a is separated from the centerof the peripheral wall 272, as shown in FIGS. 14 and 15. The windows 273and 273 are arranged around the axial center of the peripheral wall 272at even intervals.

Two guide projections 275, which project from the outer circumference ofthe peripheral wall 272, come into engagement with the guide holes 254 aof the outer walls 254 of the slide cylinder 250. The guide projections275 are arranged with a phase difference of 90° from the windows 273.

The flange 271 of the insulation ring 270 has four cutaway portions 276at regular intervals around the inner periphery thereof. The washer 280includes four projections 281 arranged at regular intervals from thelower surface to enter the cutaway portions 276. Each projection 281 hasa rising height larger than the thickness of the flange 271, thusprojecting downward from the lower surface of the flange 271, with thehorn switch gear 70D assembled (FIGS. 14 and 15).

In assembling the horn switch gear 70D, the anode 240 is first fitted onthe upper end (between the first collars 252 and the second collars 253)of the cylinder body 251 of the slide cylinder 250 to superpose theflange 241 of the anode 240 on the upper surfaces of the second collars253. The cathode 260 is fitted on the lower ends of the cylinder body251 to superpose the flange 261 of the cathode 260 on the lower surfacesof the second collars 253. At that time, they are arranged so that thecontacts 242 of the anode 240 and the contacts 262 of the cathode 260are positioned in the same phase around the axial center of the cylinderbody 251 (briefly, the contacts 242 of the anode 240 face the outersides of the contacts 262 of the cathode 260) and are arranged with aphase difference of 90° from the second collars 253. The anode 240 andthe cathode 260 are fixed to the second collars 253 with an adhesive orthe like as necessary.

The upper end of the cylinder body 251 is inserted into the guide-shaftinsertion hole 68 of the overhang 63. The first collars 252 are arrangedon the upper surface of the overhang 63, while the second collars 253are arranged on the lower surface of the overhang 63. At that time, theperiphery of the guide-shaft insertion hole 68 is clamped by the facingpieces 255 and the first collars 252. Thus, the slide cylinder 250 isfixed to the overhang 63. The flange 241 of the anode 240 is clampedbetween the overhang 63 and the second collars 253, through which thecontacts 242 are brought into conduction with the overhang 63.

The coil spring 110 is then fitted on the lower end of the cylinder body251 of the slide cylinder 250. The respective contacts 242 and 262 ofthe anode 240 and the cathode 260 are arranged outside the coil spring110.

The washer 280 is next superposed on the upper surface of the flange 271of the insulation ring 270. At that time, the projections 281 of thewasher 280 are fitted in the cutaway portions 276 of the flange 271. Theperipheral wall 272 of the insulation ring 270 is fitted on the lowerend of the coil spring 110. At that time, the upper end of the coilspring 110 is brought into contact with the flange 261 of the cathode260, while the lower end is brought into contact with the washer 280.The peripheral wall 272 is then inserted between the outer walls 254 and254 of the slide cylinder 250 while the coil spring 110 is contracted bypressure to bring the guide projections 275 into engagement with therespective guide holes 254 a of the outer walls 254. At that time, thecontacts 262 of the cathode 260 are arranged in the guide grooves 274 tothe windows 273 of the inner circumference of the peripheral wall 272,while the contacts 242 of the anode 240 are arranged along the outercircumference of the peripheral wall 272.

Thereafter, the guide shaft 50 is inserted into the cylinder body 251 ofthe slide cylinder 250 and the end of the guide shaft 50 is screwed intothe nut 17 of the extension 16. Thus, the projections 281 of the washer280 which project lower than the flange 271 of the insulation ring 270through the cutaway portions 276 are brought into contact with theextension 16, so that the contacts 262 of the cathode 260 are broughtinto conduction with the extension 16 through the washer 280, the coilspring 110, and the flange 261. The flange 51 of the guide shaft 50 andthe overhang 63 are insulated from each other by the first collars 252of the slide cylinder 250 which are arranged on the upper surface of theoverhang 63.

As shown in FIG. 14, when a horn switch gear 70D with such a structureis in a restored position, the upper parts of the windows 273 of theperipheral wall 272 interpose between the contacts 242 and 262 toseparate the contacts 242 and 262 from each other, until the modulecover 40 is pushed. Thus, the upper parts of the windows 273 of theperipheral wall 272 serve as interpositions which separate the contacts242 and 262 from each other.

As shown in FIG. 15, when the module cover 40 is pushed into a backwardposition by an occupant, the frame 60 integrated with the module cover40 moves back downwardly to move the slide cylinder 250, the anode 240,and the cathode 260 downward while contracting the coil spring 110 bypressure. Thus, the contacts 242 and 262 also move downward integrallytherewith, so that the contacts 262 are pushed outward by the inclinedsurfaces 273 a at the lower rims of the windows 273. As a result, thecontacts 242 and 262 are brought into contact with each other, therebyblowing the horn.

When the pressured applied by the occupant on the module cover 40 isreleased, the module cover 40 moves back into the restored position(FIG. 14) by the repulsive force of the coil spring 110, therebystopping the horn.

The above embodiments are constructed so that only the module cover 40moves backward when pushed. It is also possible, however, to constructthe module cover and the retainer such that they move backwardintegrally. Thus, the entire airbag system may be pushed backward toclose (or open) the contacts of the horn switch gear, thereby blowing(or stopping) the horn.

The priority applications, Japanese Application 2003-187870 (filed Jun.30, 2003) and Japanese Application 2004-002217 (filed Jan. 7, 2004) areincorporated herein by reference in their entireties.

Given the disclosure of the present invention, one versed in the artwould appreciate that there may be other embodiments and modificationswithin the scope and spirit of the invention. Accordingly, allmodifications attainable by one versed in the art from the presentdisclosure within the scope and spirit of the present invention are tobe included as further embodiments of the present invention. The scopeof the present invention is to be defined as set forth in the followingclaims.

1. A horn switch comprising: a backward moving body configured to movebackward by pressure applied by an occupant, wherein the backward movingbody comprises an airbag system or a module cover of an airbag system; astationary body facing the backward moving body; a biasing memberinterposed between the backward moving body and the stationary body forbiasing the backward moving body in a restoring direction; and at leastone pair of contact members that are configured to be brought into orout of contact from each other by a forward or backward movement of thebackward moving body, wherein the contact members are retained by thestationary body, and wherein the backward moving body comprises aninterposition which is interposed between the contact members forseparating the contact members from each other while the backward movingbody is in a restored position, and moves away from between the contactmembers to bring the contact members into contact with each other whilethe backward moving body is in a backward position.
 2. The horn switchaccording to claim 1, wherein the backward moving body comprises a guideconfigured to contact and guide at least one of the contact members tobring the contact members into contact with each other when the backwardmoving body is moved backward from the restored position.
 3. The hornswitch according to claim 1, wherein the stationary body comprises aguide for guiding at least one of the contact members to bring thecontact members into contact with each other when the backward movingbody is moved backward from the restored position.
 4. An airbag systemcomprising: a backward moving body configured to move backward bypressure applied by an occupant; a stationary body facing the backwardmoving body; a horn switch comprising: a biasing member interposedbetween the backward moving body and the stationary body for biasing thebackward moving body in a restoring direction; and at least one pair ofcontact members that are configured to be brought into or out of contactfrom each other by a forward or backward movement of the backward movingbody, wherein the contact members are retained by the stationary body,and wherein the backward moving body comprises an interposition which isinterposed between the contact members for separating the contactmembers from each other while the backward moving body is in a restoredposition, and moves away from between the contact members to bring thecontact members into contact with each other while the backward movingbody is in a backward position.
 5. The airbag system according to claim4, wherein the backward moving body comprises a guide configured tocontact and guide at least one of the contact members to bring thecontact members into contact with each other when the backward movingbody is moved backward from the restored position.
 6. The airbag systemaccording to claim 4, wherein the stationary body comprises a guide forguiding at least one of the contact members to bring the contact membersinto contact with each other when the backward moving body is movedbackward from the restored position.
 7. A horn switch comprising: abackward moving body configured to move backward by pressure applied byan occupant, wherein the backward moving body includes an airbagretainer; a stationary body facing the backward moving body; a biasingmember interposed between the backward moving body and the stationarybody for biasing the backward moving body in a restoring direction; andat least one pair of contact members that are configured to be broughtinto or out of contact with each other by a forward or backward movementof the backward moving body, wherein the contact members are movedforward or backward together with the backward moving body, and whereinthe stationary body comprises an interposition which is interposedbetween the contact members for separating the contact members from eachother while the backward moving body is in a restored position, and isconfigured to bring the contact members into contact with each otherwhile the backward moving body is in a backward position.
 8. The hornswitch according to claim 7, wherein the backward moving body comprisesa guide configured to contact and guide at least one of the contactmembers to bring the contact members into contact with each other whenthe backward moving body is moved backward from the restored position.9. The horn switch according to claim 7, wherein the stationary bodycomprises a guide for guiding at least one of the contact members tobring the contact members into contact with each other when the backwardmoving body is moved backward from the restored position.
 10. A driverside airbag system comprising: an airbag module including a gasgenerator, an airbag and an airbag retainer configured to move backwardin response to a force applied by an occupant; a horn switch positionedbetween the airbag module and a stationary body comprising: a biasingmember interposed between the airbag module and the stationary body forbiasing the airbag module in a restoring direction; and at least onepair of contact members that are configured to be brought into or out ofcontact from each other by a forward or backward movement of the airbagmodule, wherein the contact members are retained by the stationary body,and wherein the airbag module includes an interposition which isinterposed between the contact members for separating the contactmembers from each other while the airbag module is in a restoredposition, and moves away from between the contact members to bring thecontact members into contact with each other while the airbag module isin a backward position.
 11. The driver side airbag system according toclaim 10, wherein the airbag module comprises a guide configured tocontact and guide at least one of the contact members to bring thecontact members into contact with each other when the airbag module ismoved backward from the restored position.
 12. The driver side airbagsystem according to claim 10, wherein the stationary body comprises aguide for guiding at least one of the contact members to bring thecontact members into contact with each other when the airbag module ismoved backward from the restored position.
 13. The driver side airbagsystem according to claim 10, wherein the biasing member is connected tothe airbag module.
 14. The driver side airbag system according to claim10, wherein the biasing member is connected to the stationary body. 15.An airbag system comprising: a movable airbag module including a gasgenerator, an airbag and an airbag retainer; a horn switch positionedbetween the airbag retainer and a fixed vehicle structure, wherein thehorn switch includes: a biasing member interposed between the airbagretainer and the vehicle structure for biasing the airbag module in arestoring direction; and at least one pair of contact members that areconfigured to be brought into or out of contact with each other by aforward or backward movement of the airbag module; and a guide forcontacting and guiding at least one of the contact members to bring thecontact members into contact with each other when the airbag module ismoved backward from the restored position, wherein the contact membersare separated from each other while the airbag module is in a restoredposition and wherein the contact members are moved forward or backwardtogether with the airbag module.
 16. The airbag system according toclaim 15, wherein the airbag module includes an interposition which isinterposed between the contact members for separating the contactmembers from each other while the airbag module is in a restoredposition, and moves away from between the contact members to bring thecontact members into contact with each other while the airbag module isin a backward position.